Impact of suppression of thyroxine on folate status during acute antidepressant therapy

The Role of Water-Soluble Vitamins and Vitamin D in Prevention and Treatment of Depression and Seasonal Affective Disorder in Adults

Depression is a major global health concern expected to worsen by 2030. In 2019, 28 million individuals were affected by depressive disorders. Dietary and supplemental vitamins show overall favorable preventative and therapeutic effects on depression. B vitamins are crucial for neurological function and mood regulation. Deficiencies in these vitamins are linked to depression. Studies on individual B vitamins show promise in improving depressive symptoms, particularly thiamin, riboflavin, niacin, and folate. Vitamin C deficiency may heighten depressive symptoms, but its exact role is not fully understood. Seasonal Affective Disorder (SAD) is associated with insufficient sunlight exposure and vitamin D deficiency. Vitamin D supplementation for SAD shows inconsistent results due to methodological variations. Further investigation is needed to understand the mechanisms of vitamins in depression treatment. Moreover, more research on SAD and light therapy's efficacy and underlying mechanisms involving photoreceptors, enzymes, and immune markers is needed. Although dietary and supplemental vitamins show overall favorable preventative and therapeutic effects on depression, dietitians treating psychiatric disorders face challenges due to diverse study designs, making direct comparisons difficult. Therefore, this article reviews the current literature to assess the role of dietary and supplemental vitamins in the prevention and treatment of depression. This review found that, although evidence supports the role of B vitamins and vitamins C and D in preventing and treating depression, further research is needed to clarify their mechanisms of action and determine the most effective intervention strategies.

Dysphagia, texture modification, the elderly and micronutrient deficiency: a review

Dysphagia is an underlying symptom of many health issues affecting a person's ability to swallow. Being unable to swallow correctly may limit food intake and subsequently micronutrient status. The elderly may be the most at risk group of suffering dysphagia as well as most likely to be deficient in micronutrients. The use of texture-modified meals is a common approach to increasing dysphagia sufferer's food intake. The modification of food may affect the micronutrient content and currently there is a limited number of studies focusing on micronutrient content of texture-modified meals. This review considers the prevalence of dysphagia within the elderly UK community whilst assessing selected micronutrients. Vitamin B₁₂, C, D, folate, zinc and iron, which are suggested to be most likely deficient in the general elderly UK population, were reviewed. Each micronutrient is considered in terms of prevalence of deficiency, metabolic function, food source and processing stability to provide an overview with respect to elderly dysphagia sufferers.

The one-carbon-cycle and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in recurrent major depressive disorder; influence of antidepressant use and depressive state?

BACKGROUND

An important biological factor suggested in the pathophysiology of (recurrent) Major Depressive Disorder (MDD) concerns a polymorphism in a gene encoding for the MTHFR-enzyme of the one-carbon (1-C)-metabolism. Integratively investigating key 1-C-components (folate, homocysteine, vitamin B6 and B12), including the possible effects of antidepressant medication and depressive state, could provide more insight in the possible association between the MTHFR-polymorphism and recurrent MDD.

METHODS

We compared the MTHFR C677T-polymorphism together with the key 1-C-components in clinically ascertained patients with recurrent MDD (n=137) to age- and gender-matched healthy controls (n=73).

RESULTS

First, patients had lower folate (t=2.25; p=.025) as compared to controls; a difference that resolved after correction for demographics (t=1.22; p=.223). Second, patients that were depressed during sampling had lower vitamin B6 (t=-2.070; p=.038) and higher homocysteine (t=2.404; p=.016) compared to those in remission. Finally, current use of antidepressants had no influence on the 1-C-components.

CONCLUSIONS

Despite investigation of a specific recurrently depressed patient population, we found no clear associations with the 1-C-cycle, except for higher homocysteine and lower vitamin B6 during the depressed state. This suggests that 1-C-cycle alterations in MDD are state-associated, possibly resulting from high levels of acute (psychological) stress, and may provide a treatment target to reduce cardiovascular risk in this population.

Folates and S-adenosylmethionine for major depressive disorder

Interest in nonpharmaceutical supplements for treating major depressive disorder (MDD) has increased significantly, both among patients and among clinicians during the past decades. Despite the large array of antidepressants (ADs) available, many patients continue to experience relatively modest response and remission rates, in addition to a burden of side effects that can hinder treatment compliance and acceptability. In this article, we review the literature on folates and S-adenosylmethionine (SAMe), 2 natural compounds linked in the 1-carbon cycle metabolic pathway, for which substantial evidence supports their involvement in mood disorders. Background information, efficacy data, proposed mechanisms of action, and side effects are reviewed. Based on existing data, supplementation with SAMe, as well as with various formulations of folates, appears to be efficacious and well tolerated in reducing depressive symptoms. Compared with other forms of folates, 5-methyltetrahydrofolate (L-methylfolate or 5-MTHF) may represent a preferable treatment option for MDD given its greater bioavailability in patients with a genetic polymorphism, and the lower risk of specific side effects associated with folic acid. Although further randomized controlled trials in this area appear warranted, SAMe and L-methylfolate may represent a useful addition to the AD armamentarium.

Folic acid administration produces an antidepressant-like effect in mice: evidence for the involvement of the serotonergic and noradrenergic systems

Clinical studies have shown that folic acid plays a role in the pathophysiology of depression. However, very few studies have investigated its effect in behavioral models of depression. Hence, this study tested its effect in the forced swimming test (FST) and the tail suspension test (TST), two models predictive of antidepressant activity, in mice. Folic acid administered by oral route (p.o.) produced a reduction in the immobility time in the FST (50-100mg/kg) and in the TST (10-50mg/kg). The administration of folic acid by i.c.v. route also reduced the immobility time in the FST (10nmol/site) and in the TST (1-10nmol/site). Both folic acid administered by oral and i.c.v. route produced no psychostimulant effect, which indicates that its antidepressant-like effect is specific. Pretreatment of mice with p-chlorophenylalanine methyl ester (PCPA; 100mg/kg, i.p., an inhibitor of serotonin (5-HT) synthesis, for 4 consecutive days), ketanserin (5mg/kg, i.p., a 5-HT(2A/2C) receptor antagonist), prazosin (1mg/kg, i.p., an alpha(1)-adrenoceptor antagonist) or yohimbine (1mg/kg, i.p., an alpha(2)-adrenoceptor antagonist) prevented the anti-immobility effect of folic acid (50mg/kg, p.o.) in the FST. Moreover, the pretreatment of mice with WAY100635 (0.1mg/kg, s.c., a selective 5-HT(1A) receptor antagonist) blocked the decrease in immobility time in the FST elicited by folic acid (50mg/kg, p.o.), but produced a synergistic effect with a subeffective dose of folic acid (10mg/kg, p.o.). In addition, a subeffective dose of folic acid (10mg/kg, p.o.) produced a synergistic antidepressant-like effect with fluoxetine (10mg/kg, p.o.) in the FST. Overall, the results firstly indicate that folic acid produced an antidepressant-like effect in FST and in TST and that this effect appears to be mediated by an interaction with the serotonergic (5-HT(1A) and 5-HT(2A/2C) receptors) and noradrenergic (alpha(1)- and alpha(2)-adrenoceptors) systems.

Treatment of depression: time to consider folic acid and vitamin B12

We review the findings in major depression of a low plasma and particularly red cell folate, but also of low vitamin B12 status. Both low folate and low vitamin B12 status have been found in studies of depressive patients, and an association between depression and low levels of the two vitamins is found in studies of the general population. Low plasma or serum folate has also been found in patients with recurrent mood disorders treated by lithium. A link between depression and low folate has similarly been found in patients with alcoholism. It is interesting to note that Hong Kong and Taiwan populations with traditional Chinese diets (rich in folate), including patients with major depression, have high serum folate concentrations. However, these countries have very low life time rates of major depression. Low folate levels are furthermore linked to a poor response to antidepressants, and treatment with folic acid is shown to improve response to antidepressants. A recent study also suggests that high vitamin B12 status may be associated with better treatment outcome. Folate and vitamin B12 are major determinants of one-carbon metabolism, in which S-adenosylmethionine (SAM) is formed. SAM donates methyl groups that are crucial for neurological function. Increased plasma homocysteine is a functional marker of both folate and vitamin B12 deficiency. Increased homocysteine levels are found in depressive patients. In a large population study from Norway increased plasma homocysteine was associated with increased risk of depression but not anxiety. There is now substantial evidence of a common decrease in serum/red blood cell folate, serum vitamin B12 and an increase in plasma homocysteine in depression. Furthermore, the MTHFR C677T polymorphism that impairs the homocysteine metabolism is shown to be overrepresented among depressive patients, which strengthens the association. On the basis of current data, we suggest that oral doses of both folic acid (800 microg daily) and vitamin B12 (1 mg daily) should be tried to improve treatment outcome in depression.

The MTHFR C677T polymorphism is associated with depressive episodes in patients from Northern Ireland

Low plasma folate and its derivatives have been linked with depressive disorders in studies dating back over 30 years. A thermolabile variant (677C>T) of the enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR) is associated with low serum folate. The present study aimed to explore whether the thermolabile variant of MTHFR is associated with a vulnerability to depressive episodes. MTHFR C677T genotype frequencies in a cohort of patients (mean age 48 years) with depressive disorder (n = 100) were compared with those in age- and sex-matched controls. Serum levels of folate, homocysteine and vitamin B(12) were also compared between groups. The thermolabile variant of MTHFR was significantly more common in the group with a history of depressive disorder (P= 0.03). Serum levels of folate, homocysteine and vitamin B(12) did not differ significantly between groups. A MTHFR C677T genotype is associated with increased risk of depressive episodes in this homogenous patient population.

S-adenosyl-methionine in depression: a comprehensive review of the literature

As many as 29% to 46% of patients with major depressive disorder (MDD) show only partial or no response to an adequate course of an antidepressant. The current practice is to increase the dose, switch to another antidepressant, or to combine the initial antidepressant with an antidepressant of a different class or a non-antidepressant agent. A growing number of studies have also been directed toward exploring the potential use of augmenting traditional antidepressants with nonpharmaceutic supplements, or even using such supplements as monotherapy for depression. S-adenosyl-methionine (SAMe) is one such compound. Compared with many other nonpharmaceutic supplements, SAMe has been extensively studied, and impressive literature extending back three decades suggests the antidepressant efficacy of SAMe. In the present work, the authors summarize the literature, focusing on the potential role of SAMe and its precursors in the pathophysiology of MDD, followed by a review of studies examining the use of SAMe for the treatment of MDD. Finally, the authors propose a model that would explain the actions of SAMe in the central nervous system.

Short-term folate, vitamin B-12 or vitamin B-6 supplementation slightly affects memory performance but not mood in women of various ages

Based on research demonstrating associations between folate, B-12 and B-6 vitamins and cognition and mood, we investigated the effects of short-term supplementation in 211 healthy younger, middle-aged and older women who took either 750 microg of folate, 15 microg of vitamin B-12, 75 mg of vitamin B-6 or a placebo daily for 35 d. In addition, we examined associations between dietary intake of these vitamins and cognition and mood. Usual dietary intake status was estimated using a retrospective, self-report, quantified food frequency questionnaire. Participants completed alternate forms of standardized tests of cognitive processing resources, memory, executive function, verbal ability and self-report mood measures before and after supplementation. Supplementation had a significant positive effect on some measures of memory performance only, and no effect on mood. Dietary intake status was associated with speed of processing, recall and recognition and verbal ability.

Sleep deprivation therapy in depressive illness and Parkinson's disease

1. Sleep deprivation is commonly associated with feelings of fatigue and cognitive impairment. 2. Patients with depressive illness, however, often experience mood improvements under these same conditions. 3. Other studies now show that tremor and rigidity, in patients with Parkinson's disease, are also improved by sleep depression therapy. 4. The neural substrates which underlie these effects are unclear. Some recent evidence, however, suggests that sleep deprivation may activate mechanisms which are otherwise typical of conditions of metabolic stress. 5. A common feature of these mechanisms is the suppression of cholinergic activity which is thought to be excessive, in relation to monoamine transmission, in both depression and Parkinson's disease.